Insulator.



No. 807,307. PATENTED DBO.`12, 1905.

L. MGCARTHY.

INSULATOR.

A APPLIOATIONHLBD PEB.18. 1,904.

corneys.

UNITED 4STATES PATENT OFFICE.

INSULATOR.l

Specification of Letters Patent.

Patented Dee. 12, 1905.

Application filed February 18, 1904. Serial No. 194,155.

proved insulator which shall be especially adapted for use out of doors or in situations where it is to be exposed to moisture.

In the installation of incandescent electric lights for street-lighting and the like the current employed is frequently taken from a line of hi h potential by the employment of a trans ormer. In such cases it is desirable that the lamp should be separated from the supporting-bracket or iixture by a strong and durable insulator, which shall be Substani tially free from moisture throughout atleast a considerable portion of its exterior surface and which shall afford thorou h insulation against the passage of a owe l current in order that thel danger whic might result from a current on the lamp side of theiiXture passing into the supporting-bracket may be reduced to a minimum.

The invention is fully set forth in the following description, taken in connection with the accompanying drawings, and the novel features thereof are pointed outand clearly defined in the claims at the close of this specif iication.

The, accompanying drawing illustrates an embodiment of my invention utilized in connection with an incandescent electric lamp and its supporting-bracket intended for outof-dors use. The said drawing shows, artly in Asection and partly in elevation, a ampsocket and portion of a lam an insulator embodying m invention, an a portion of-a bracket arm di support.

Referringto' the said drawing, A designated a portion ofl a supporting-bracket of common construction, the, said bracket-arm being hollow for the passageof thewires 1 and 2, which supply the lamp. `The end y'of the said bracket to which thel insulator is attached is screw-threaded, as shown at 3. The lamp is shown at B and its socket at D, these being of any well-known construction. In the form shown the lamp-socket is provided with -a threaded sleeve or tubular portion 4, which is adapted for attachment to the insulator. The insulator comprises a mass of molded nsulating com osition C, Which is of thepeculiar bell or rusto-conical shape shown and which is provided at thelower and larger end `with a skirt 5, rojecting downwardly well below the metal ic connection of the insulator. Inside of the skirt 5 I provide a short annular projection or skirt 6, separated from the skirt 5 by an intervening crowning or vcurved contour space 7. On the inside of the shortskirt or projection 6 occurs another interval or separate space 8, which separates the said short skirt from the metallic threaded sleeve 9, which is embodied i-n the mass or body C of insulating material and serves as a secure means of connecting Socket-sleeve 4 with the said insulator. Embedded in the upper end or top of the insulator-body C is` a cylindrical metallic piece or sleeve 10, which is interiorly threaded andn adapted tol be screwed onto the threaded end of a supporting-bracket A; In practice the threaded sleeve or connection 10 1s usually considerably larger in diameter than the threaded-sleeve connection 9. The said metallic sleeves 9 and 10 are at the oposite ends of a hole or passage 11, which is ocated centrally of the mass of insulating material C and which affords ample accommodation for the lamp-sup ly wires 1 and 2, thus greatly facilitatlng t e attachment of the lamp-socket to the wires 1 and 2 and to the insulator. If the passage 11 ,is not of ample size, it does not affordroom for any eXtra length of wires 1 and 2, which requires to be pulled out in order to make proper attachment with the socket. The said passage, therefore, not only serves as a means of permitting the Wires to pass through the insula-l v which permits a better and much more speedy adjustment of thelamp-socket by the operator who is installing or repairing the construction. The surplus4 length of wires 1 and 2\ above referred to is indicated by the coiled or bent portions thereof at 12 and 13.

In' connection with the lamp-socket a reflector o1" other similar device of common construction (not Shown) may be employed, as will be clear. l

The conical or tapering shape of the body of the insulator C carries descending moisture wellaway from the metallic parts at the lamp end of the insulator, and the skirt permits itV to drip from the insulatorand prevents it creeping upwardly on the'inside of the skirt. The slight moisture which may collect by deposition is shed by the inner suring a dry under body, and thus prevent-v ing or reducing to a minlmum the danger of a current asslng over the exterior surface of the insu ator between the lamp-socket and the supporting-bracket.

W'hat I claim is- An insulator comprising a body portion of molded composition having formed thereon one or more skirts or projections for the shedding of moisture, and having an opening therethrough to permit the passage of supply- Wires of a'size sufficient for the reception of surpluswires, and independent metallic-sleeve connections insulated from each other at each end of said opening and forming a continuation thereof, said metallic connections being molded into said body portion and serving as a means of attaching the said insulator to the contiguous portions of the construction.

In testimony whereof I aflix my signature in presence of two witnesses'.

LOUIS MCOARTHY. 

